Human ingenuity has created a world that the mind cannot master. Have we finally reached our limits?

Despite the vastness of the sky, airplanes occasionally crash into each other. To avoid these catastrophes, the Traffic Alert and Collision Avoidance System (TCAS) was developed. TCAS alerts pilots to potential hazards, and tells them how to respond by using a series of complicated rules. In fact, this set of rules — developed over decades — is so complex, perhaps only a handful of individuals alive even understand it anymore. When a TCAS is developed, humans are pushed to the sidelines and, instead, simulation is used. If the system responds as expected after a number of test cases, it receives the engineer’s seal of approval and goes into use.